Wide Area Computer Networks (WAN), in particular the INTERNET network, allow users to communicate multimedia information therebetween. For Example, the Internet Phone, commercially available from VocalTec Inc. of New Jersey, enable audio conferencing between two parties using two computer stations connected to the INTERNET and equipped with the INTERNET PHONE.TM. application.
In another application, multi-station multi-media conferencing Is provided. In multi-station conferencing, a number of users employ their computer station in order to hold a conference. Generally speaking, two types of multi-station conferencing exist, namely, full-duplex conferencing in which each user may speak and hear audio information, i.e. is able to simultaneously transmit and receive voice packets, and half-duplex conferencing in which one station is determined to be the current transmitting station at a time.
Full-duplex conferencing requires a mixing mechanism by which voice packets transmitted by each station are mixed in a network server so as to avoid the need to resolve according to predetermined criteria which participant will be the active participant. Obviously, mixing mechanisms directed to full duplex conferencing are costly and difficult to implement and require in addition a supplemental mechanism for self-hearing cancellation, such as an echo canceling algorithm.
Half-duplex conferencing requires a mechanism which will resolve who will be the user allowed to speak to all other at any particular time. In prior art half-duplex and conferencing, a resolving mechanism based on an arbitration procedure between voice packets, for example the procedure described in U.S. Pat. No. 5,434,797 to Barris is implemented.
Another drawback associated with conferencing systems in general and with multi-media multi-station conferencing in particular is that it is sometimes difficult for one participant to recognize who is the current participant. This problem is particularly difficult in multi-station network conferencing, such as in INTERNET multi-station conferences where participants which are not familiar with each other have to recognize who is the current participant.